Photoresist conditioning with hydrogen ramping

Abstract

A method for etching a feature in an etch layer through a photoresist mask over a substrate is provided. A substrate with an etch layer disposed below a photoresist mask is placed in a process chamber. The photoresist mask is conditioned, wherein the conditioning comprises providing a conditioning gas comprising a hydrogen containing gas with a flow rate and at least one of a fluorocarbon and a hydrofluorocarbon with a flow rate to the process chamber; and energizing the conditioning gas to form the conditioning plasma. The conditioning plasma is stepped. An etch plasma is provided to the process chamber, wherein the etch plasma is different than the conditioning plasma. A feature is etched in the etch layer with the etch plasma.

1. A method for etching a feature in an etch layer through a photoresist mask over a substrate, comprising:
 placing a substrate with an etch layer disposed below a photoresist mask in a process chamber; 
 conditioning the photoresist mask, comprising:
 providing a conditioning gas comprising a hydrogen containing gas with a flow rate and at least one of a fluorocarbon and a hydrofluorocarbon with a flow rate to the process chamber; 
 energizing the conditioning gas to form the conditioning plasma; 
 ramping the conditioning gas so that a ratio of the flow rate of the hydrogen containing gas and the flow rate of the at least one of the fluorocarbon and hydrofluorocarbon is ramped down; and 
 stopping the conditioning plasma; 
 
 providing an etch plasma to the process chamber, wherein the etch plasma is different than the conditioning plasma; and 
 etching a feature in the etch layer with the etch plasma. 
 
     
     
       2. The method, as recited in  claim 1 , wherein the hydrogen containing gas is H 2 . 
     
     
       3. The method, as recited in  claim 2 , wherein, the conditioning plasma is an in situ plasma. 
     
     
       4. The method, as recited in  claim 3 , wherein a BARC is disposed between the photoresist mask and the etch layer, wherein the conditioning of the photoresist mask opens through the BARC. 
     
     
       5. The method, as recited in  claim 4 , wherein the ramping the conditioning gas is a non-linear ramping. 
     
     
       6. The method, as recited in  claim 4 , wherein the conditioning provides at least 100:1 photoresist selectivity when opening the BARC. 
     
     
       7. The method, as recited in  claim 6 , wherein the etch layer is a dielectric layer. 
     
     
       8. The method, as recited in  claim 1 , wherein the hydrogen containing gas is H 2  and the at least one of a fluorocarbon and hydrofluorocarbon is CF 4 . 
     
     
       9. The method, as recited is  claim 7 , wherein the conditioning gas has an initial H 2  to CF 4  flow ratio between 1:10 and 2:1 and a final H 2  to CF 4  flow ratio between 0 and 1:20. 
     
     
       10. The method, as recited in  claim 1 , wherein the hydrogen containing gas is H 2  and the at least one of a fluorocarbon and hydrofluorocarbon is CF 4 , wherein the conditioning plasma is an in situ plasma. 
     
     
       11. The method, as recited in  claim 10 , wherein the conditioning gas has an initial to CF 4  flow ratio between 1:10 and 2:1 and a final H 2  to CF 4  flow ratio between 0 and 1:20. 
     
     
       12. A method for etching a feature in an etch layer through a photoresist mask over a substrate, comprising:
 placing a substrate with an etch layer disposed below a photoresist mask in a process chamber; 
 conditioning the photoresist mask, comprising:
 providing a conditioning gas comprising a hydrogen containing gas with a flow rate and at least one of a fluorocarbon and a hydrofluorocarbon with a flow rate to the process chamber; 
 energizing the conditioning gas to form the conditioning plasma, wherein a BARC is disposed between the photoresist mask and the etch layer, wherein the conditioning of the photoresist mask opens the BARC with at least 100:1 photoresist selectivity when opening the BARC; and 
 stopping the conditioning plasma; 
 
 providing an etch plasma to the process chamber, wherein the etch plasma is different than the conditioning plasma; and 
 etching a feature in the etch layer with the etch plasma. 
 
     
     
       13. The method, as recited in  claim 4 , wherein the etch layer is a dielectric layer. 
     
     
       14. A method for etching a feature in an etch layer through an antireflective coating and a photoresist mask over a substrate, comprising:
 placing a substrate with an etch layer disposed below an antireflective coating and a photoresist mask in a process chamber; 
 opening the antireflective coating, comprising:
 providing a conditioning gas comprising a hydrogen containing gas with a flow rate and at least one of a fluorocarbon and a hydrofluorocarbon with a flow rate to the process chamber; and 
 energizing the conditioning gas to form the conditioning plasma; and 
 stopping the conditioning plasma after the antireflective coating is opened; 
 
 providing an etch plasma to the process chamber, wherein the etch plasma is different than the conditioning plasma; and 
 etching a feature in the etch layer with the etch plasma through the antireflective coating and photoresist mask. 
 
     
     
       15. The method, as recited in  claim 14 , further comprising ramping the conditioning gas so that a ratio of the flow rate of the hydrogen containing gas and the flow rate of the at least one of the fluorocarbon and hydrofluorocarbon is ramped down. 
     
     
       16. The method, as recited in  claim 15 , wherein the hydrogen containing gas is H 2 . 
     
     
       17. The method, as recited in  claim 15 , wherein the conditioning plasma is as in situ plasma. 
     
     
       18. The method, as recited in  claim 15 , wherein the conditioning provides at least 100:1 photoresist selectivity when opening the ARC. 
     
     
       19. The method, as recited in  claim 15 , wherein the hydrogen containing gas is H 2  and the at least one of a fluorocarbon and hydrofluorocarbon is CF 4 . 
     
     
       20. The method, as recited in  claim 19 , wherein the conditioning gas has an initial H 2  to CF 4  flow ratio between 1:2 and 5:4 and a final H 2  to CF 4  flow ratio between 0 and 1:20.